Amethyst

Amethyst (Silicon Dioxide, SiO2)

Rock Type: mineral

Amethyst

Physical Properties

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & Geological History

Formed in hydrothermal veins or geodes when silica-rich water enters rock cavities (often volcanic basalt) and cools over time. The purple color comes from iron impurities and irradiation.

Uses & Applications

Primary use is in jewelry (gemstones), carvings, and as decorative mineral specimens for collectors. It is also a popular stone for metaphysical practitioners.

Geological Facts

The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness. It is the February birthstone and was once considered as valuable as diamonds until large deposits were found in Brazil.

Field Identification & Locations

Identify by its characteristic purple hue and lack of cleavage. Look for hexagonal crystal terminations in raw specimens. Commonly sourced from Brazil, Uruguay, Zambia, and South Korea.

Identified on: 4/23/2026

Mode: Standard